This invention relates to foldable vehicles, and has particular reference to a bicycle that is capable of being reduced to a folded, portable package that can be carried by the user and stored in a relatively small space. Included in the broad category of vehicles to which the invention relates are collapsible and so-called "knock-down" vehicles, and vehicles which may be motor driven as well as driven by pedal-and-sprocket drives, and particularly motorized bicycles of the type known as mopeds.
For many years, efforts have been made to provide a practical foldable and portable bicycle for use in travel to and from bus stops, train stations, and the like, and to and from offices, grocery markets and other places of business, as well as for other typically short trips that can conveniently be made by bicycle, except for the problem of storage of the bicycle during travel on another vehicle, or during shopping, work, or other activity at the traveller's destination. Both convenience of travel and energy-saving economy are important motivating factors in this respect, and with the current increases in the cost of other forms of travel, and particularly in the cost of gasoline, these factors have become even more important than in the past.
The general objective in this field is to enable the cyclist to fold and collapse the bicycle quickly and easily into a compact and lightweight package that can be carried by the cyclist onto another vehicle, or into an office or shop, and stowed in available space such as under a seat, in a locker, or in some other relatively small space. Of course, it is also important for the cyclist to be able to unfold the bicycle and prepare it quickly and easily for use, and for the bicycle to perform satisfactorily in the unfolded condition, in terms of riding ease and comfort, safety, durability and other operating characteristics. In addition, it is important that the bicycle can be mass-produced at reasonable cost.
Many prior bicycles have been proposed in this general field, all designed to attempt to fulfill the need for a practical folding bicycle. One such bicycle is shown in this inventor's U.S. Pat. No. 4,067,589. Each of these bicycles, however, has shortcomings that prevent it from being the optimum bicycle of this type.
In the prior bicycles, including the one disclosed in the foregoing patent, the main components of the bicycle that can be folded and collapsed are the frame, the handlebar and steering assembly, the seat assembly, and in some cases the drive assembly, including the sprocket/pedal assembly. The wheels of the bicycle constitute the principal components that cannot practically be reduced in size, and thus typically are made relatively small as compared to conventional adult bicycles. To adapt a small-wheeled bicycle for use by an adult, the handlebar and steering assembly and the seat assembly extend upward to a conventional height. Except for the effect on "ride" on a rough surface, the relative disadvantages of the small wheels are not significant when the bicycle is equipped with a drive assembly providing a high front-to-rear drive ratio.
The available foldable and collapsible bicycles suffer from a number of deficiencies, including inconvenient and time-consuming complexity in the folding and unfolding operations, excessive weight that is required in some designs for safe and durable construction, less-than-adequate rigidity for safe operation with other designs, and relative bulkiness or awkward shape in the folded condition with most designs.
The objective of the present invention is to provide a foldable and portable bicycle in which these characteristics are optimized so that the bicycle is quicker and easier to fold and unfold, is light in weight yet sturdy, durable and safe for normal operation, and is more compact, tightly folded and held, and convenient to handle in the folded condition for greater ease of storage and carrying, and as optional benefits, also has convenient storage elements for use during riding and is capable of being rolled as a cart both in the folded condition and in a partially folded condition in which the bicycle can be used to carry merchandise such as groceries. In addition, important objectives are to provide such a bicycle that can be mass-produced using conventional production technology to sell at a competitive price, and also can be adjusted to or provided in a full range of different riding configurations with respect to handlebar and seat positions, drive ratio and the like.